| Term | Definition |
|---|
| macroevolution | evolutionary change on grand scale |
| microevolution | evolution within a species; changes in gene frequency |
| adaptation | increases the likelihood of survival and reproduction of a particular genetic trait in a population |
| punctuated equilibrium | evolution appears in spurts |
| gradualism | gradual evolutionary change |
| Lamarck | traits are acquired and then passed on to offspring |
| fossils | preserved remains, tracks, or traces of once-living organisms |
| molecular clocks | a technique in genetics, which researchers use to date when two species diverged |
| homologous structures | have different structure and function but are all derived from the same body part present in a common ancestor |
| analogous structure | resemble each other as a result of parallel evolutionary adaptations to similar environments; convergent evolution |
| alleles | alternate forms of a gene |
| allele frequencies | original genotype propotions |
| vestigial organs | structures that are no longer in use |
| Hardy- Weinberg equilibrium | A population that is not evolving; proportions do not change |
| frequency | proportion of individuals falling within a category in relation to the total number of individuals being considered |
| p2 + 2pq + q2 | equation used to calculate allele frequencies |
| mutation | error in replication of a nucleotide sequence in DNA |
| migration | the movement of individuals from one population into another |
| genetic drift | random loss of alleles |
| bottleneck effect | a sudden decrease in population size to natural forces |
| population genetics | study of the properties of genes in a population |
| founder effect | small group of individuals establishes a population in a new location |
| nonrandom mating | mating that occurs more or less frequently than expected |
| inbreeding | mating with relatives |
| outbreeding | mating outside of relatives |
| artificial selection | breeder selects for desired characteristics |
| natural selection | environment selects for adapted characteristics |
| stabilizing selection | acts to eliminate both extreme phenotypes |
| disruptive selection | acts to eliminate intermediate phenotypes |
| directional selection | acts to elimiate a single extreme phenotype |
| sickle-cell anemia | hereditary disease affecting hemoglobin molecules in teh blood |
| heterozygote advantage | sickle-cell anemia is an example: survival of heterozygotes out-weighs death in homozygotes |
| speciation | species-forming process |
| Ernst Mayr | coined "biological species concept" |
| biological species concept | "species are groups of actually or potentially intebreeding natural populations which are reproductively isolated form other such groups" |
| reproductively islolated | population whose members do not mate with each other or unable to produce fertile offspring |
| reproductive isolating mechanisms | barriers that prevent genetic exchange between species |
| prezygote isolating mechanisms | prevents the formation of zygotes |
| postzygote mechanisms | prevents the proper functioning of zygotes after they have formed |
| allopatric speciation | the differenciation of geographically isolated population into distinct species |
| sympatric speciation | the differenciation of populations within a common geographic area into distinct species |
| polyploidy | more than two sets of chromosomes |
| autopolyploidy | all chromosomes from one species |
| allopolyploidy | chromosomes derived from two species, vis hybridization |
| geographic isolation | separated by a physical barrier |
| ecological isolation | species occur in the same area but occupy different habitats |
| behavior isolation | species differ in the mating rituals |
| temporal isolation | species reproduce in different seasons or at different times of the day |
| mechanical isolation | structual differences between species prevent mating |
| emigration | the movement of individuals into a population |
Combine with other sets
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